I took the kid's threatening to enter a house as the point where confrontation was forced. The officer had to choose between letting the kid go, finally taking action to stop him, or risk the situation escalating into one much more serious.
I picked the taser as the opening move simply because that's what the article describes.
(aside -- there are all sorts of arcane rules involved in dealing with private property. For all I know, letting the kid into a house might actually be the same thing as letting the kid go)
Why the risk? He has already faced a belligerent and dismissive response from the kid and hostile intervention from the neighbors. I don't find any difficulty imagining lots of ways things could spiral out of control if things continued onto confronting the owners of the house or waiting for backup to arrive.
If you and Chris don't see the apparent belligerence and violence in my scenario's kid's words, then you simply aren't imagining them the way they I was when I wrote the scenario. When the kid forces through his stutter, he is literally yelling those words, and this is accompanied with him jerking his face towards the cop. I had also imagined him with a somewhat naturally loud voice. I picked this particular speech impediment because I have actually heard ones that aren't too dissimilar, albeit more subdued. (it's not hard to revise the scenario to one where there kid is expressing genuine belligerence, but with similar words and intents)
(another aside: while I was making a scenario that agreed with the article, I wasn't trying to make one that agreed with the court document)